What is a Pool Pump Curve

What exactly is a pool pump curve?  A swimming pool pump curve is a diagram that shows how many gallons of water can be moved by a particular pump through pipe at a given resistance. A typical pump curve diagram will have a vertical line to the left  expressing the total dynamic head in feet of water (resistance) and a horizontal line that shows the gallons per minute being moved. Using this basic layout each manufacturer will typically take a series of there pumps and draw lines across the charts showing each pumps performance.  This is what we then refer to as the performance curve of the pump. Then the manufacturers draw a "C" shaped or "U" shaped curve across the performance lines of each pump. The resulting diagram then shows us how many gallons of water per minute a pump can move at a given resistance in the most efficient manner.

When sizing a pump it’s important to review pump curve charts to find the most efficient pump to meet your demands.  The key to using these charts is to find the pumps that meet the flow demands at a given resistance within the "C" or "U" shaped curve. You may find on the chart that many of the pumps can meet the gallons per minute you require, but their performance falls outside of the "U" or "C" shaped curve, which means they will not run as efficiently costing you more money to run and potential noise issues when operating.

When selecting your pump if you are in the middle of two pump curves you should choose the pump that is slightly larger especially if you have water features in your pool. These charts can be complicated to some individuals and manufacturers understand this. This is why many manufacturers have been designing variable speed pumps for residential owners. These pumps allow sizing to be adjusted on site with just one pump and ensure maximum energy savings and flow rate requirements are met. If your concerned about achieving maximum flow and efficiency and don't understand pump curves take a look at an Intelliflo variable speed pump

Below is an example of a pump curve chart. It shows both low head (low restrictive system) and medium to high head (More restrictive pipe systems) on one diagram.


In this chart if we were looking for a pump to fit into a system that had total dynamic head of 70 and we needed to get 60 gallons per minute we would choose pump curve G to meet the demands of our system.